Device for stamping code numbers



Jan. 30, 1962 P. F. NICHOLS 3,018,720

DEVICE FOR STAMPING CODE NUMBERS Filed June 12, 1959 2 Sheets-Sheet lJaye/ f aw P5727? f. /V/ cl/OLS 3 I ifl y Jan. 30, 1962 P. F. NICHOLSDEVICE FOR STAMPING CODE NUMBERS 2 Sheets-Sheet 2 Filed June 12, 1959Arluufl II THU h wlrlll uuuuw WH HN ZFrdezzZor 1 57-531? Mex/0L5 Unitedrates Patent 3,018,720 DEVICE FOR STAMPING CODE NUMBERS Peter F.Nichols, Montreal, Quebec, Canada, assignor to Bowers Machine CompanyLimited, Montreal, Quebec, Canada Filed June 12, 1959, Ser. No. 820,0434 Claims. (Cl. 101-41) The present invention relates to stamping devicesand more particularly to devices of this nature adapted for stamping acode indicia on each of a series of articles as they are continuouslyfed along a moving conveyor belt.

As is well known, there is a problem in effectively and clearly stampinga number or symbol on a surface that is moving during the stampingoperation, particularly when the stamping is performed as part of aproduction line assembly and by automatic stamping equipment. Since, inmost cases the stamping equipment is stationary the movement of thearticles as the stamp is being applied results in a smearing orelongation of the required symbol. Attempts have been made to overcomethis problem by providing stamping equipment which rotates or moves withthe conveyed articles, the idea being that the stamp and article travelin unison while the stamp is applied. These arrangements are somewhatcumbersome and complicated and do not lend themselves readily to highspeed conveying arrangements. Other arrangements have been proposed toaccelerate the stamping action to a point where the actual stampingcontact is so brief that the smearing is reduced to a minimum but theseagain in general require complicated and costly equipment which presentsproblems in their installation in existing production line conveyorsystems.

The present invention recognizes these problems and aims to provide asatisfactory solution by furnishing a simple compact stamping devicewhich can be readily installed on any production line conveyor set-upand which can also be readily adjusted to stamp articles of varyingsizes.

More specifically, the present apparatus performs a stamping operationthrough the action of an electrically or air-operated plunger depressinga spindle on the lower end of which is mounted a stamping device. Afeature of this apparatus is that it is constructed and adjusted so thatthe stroke of the plunger is always shorter than the distance betweenthe surface of the article to be stamped and the stamping device so thatwhen the plunger reaches the end of its stroke the spindle continues byits own weight and momentum. This causes the stamping device to come inmomentary contact with the article and then rebound to its originalposition.

In addition the stamping or printing device proper is constructed sothat a slight rolling effect is achieved upon contact with the articleso that the actual printing takes" place progressively in a directionopposite to the direction of travel so as to further minimize thepossibility of blurring. This is accomplished by having the printinghead mounted for restricted pivotalmovement and resiliently biasing itso that a front edge of the printing face is. first aligned with and inthe printing motion first engages the surface of the article. This frontedge of the printing face is provided with a driving or engagement barof rubber or the like so that upon contact with the moving article thefrictional engagement causes the printing head to pivot bringing theremainder of the printing face progressively into contact with thearticle. The resilient bias is arranged so that immediately the printingface starts to pivot it acts to accelerate the printing movement and onthe up stroke acts to cock or return the printing face to the engagingposition. In one preferred construction, a solenoid having a slidingarmature and a stamp supporting spindle are aligned one above the otherbut are not connected and the spindle is spring biased towards thesolenoid so that the stamping action is very rapid. A similar effect isachieved with an air cylinder and piston in place of the solenoid. Thesolenoid or air cylinder is triggered by suitable means, for example avHaving thus generally described the nature of the invention, particularreference will be made to the accompanying drawings showing by way ofillustration a preferred embodiment thereof, and in which:

FIGURE 1 is a perspective plan view showing by way of illustration andsomewhat diagrammatically a portion of a can-conveying arrangementhaving a stamping arrangement according to the invention mounted in thepath of the conveyor.

FIGURE 2 is a front view of the arrangement shown in FIGURE 1 with thecasing broken away to show the internal mechanism more clearly with thecan guide rails also shown in section to illustrate the relativeposition or. the can and the controlling micro-switch.

FIGURE 3 is a side view of the construction shown in- FIGURE 2 with thecasing in section to show the mechanism more clearly.

FIGURE 4 is a view of the upper portion of the arrangement shown inFIGURE 2 with segments in section to illustrate in more detail theconstruction and relative positions of the working elements of thestamping mecha nism as they would appear in normal at rest position.

FIGURE 5 is a cross-sectional side view of the construction shown inFIGURE 4 with the working elements shown as they would appear at the endof the solenoid plunger stroke with the marking stamp in initial contactwith the top of a can.

FIGURE 6 is a fragmentary view corresponding to FIGURE 5 to show in fulllines the beginning of the up movement of the stamping head bringing itinto contact with the stop, and in broken lines the position of theprinting head in inking position after it has passed the stop.

FIGURE 7 is a sectional view of the printing head to illustrate themounting and resilient bearing of the pivotally mounted stamp bearingportion.

FIGURE 8 is a bottom plan view of the stamp portion showing theresilient friction or delivery bar.

FIGURE 9 is an enlarged detail view partially in sectionrof a portion ofthe construction as shown in FIGURE 2 to illustrate the resilientbiasing of the pivotal stamp supporting portion in more detail.

FIGURE 10 is a diagram of a suitable electric circuit for the form ofapparatus utilizing an electrical solenoid as the main actuating member.

FIGURE 11 is a sectional view of the upper portion of the stampingmechanism showing the alternate use of an air cylinder and piston as themain actuating member.

FIGURE 12 is a detail view of the lower end portion of an actuatingplunger showing a spindle return dampening arrangement which may beutilized in combination with either actuating member.

With particular reference to FIGURES l, 2 and 3 of the drawings, astamping arrangement in accordance with the invention is shown as beingincorporated in a conveying system carrying a plurality of cans, forexample cans operational point.

For the purpose of illustration the stamping mechanism is shown as beingcompletely enclosed in a casing or housing and being mounted on suitablestandards 12 above the run of the conveyor belt 14. The arrangementshown supports a stamping head provided with removable rubber type forthe stamping of the required code indicia on the cans which will bedescribed in more detail later.

As previously mentioned, the essential elements of the construction ofthe invention comprise of a printing head 20 mounted on a spring loadedsliding spindle 22 driven by a suitable plunger or piston, in theconstruction shown a solenoid 24 having a sliding core 26, and actuatedby the triggering of a micro-switch 28, mounted in a suitable positionin the path of the conveyor 14. A feature of this arrangement is thatthe stroke of the solenoid core 26 is not sufficient to bring theplunger or spindle 22 and the printing head 20 mounted thereon all theway down to meet the article, in the present case the top of one of thecans A." Accordingly, when the core 26reaches the end of its stroke thespindle 22 continues by its own momentum. This causes the stamping head20 to momentarily contact the top of the can A and then by the action ofthe spring 23 rebound to its original position.

During this stamping action the printing head 20 performs a slightpivotal movement to bring the type face into progressive contact withthe face of the can as will be described in more detail later.

Withparticular reference to FIGURES 4 and 5, the main elements areconstructed and assembled in the following manner so as to provide meanswhereby the location of the mechanism and stroke can be readily adjustedto suit any variation in conveyor or article size.

As previously mentioned, the housing 10 is mounted on a horizontalstandard member 12 by attachment of the back plate 11 with a nut andbolt assembly 15. The back plate 11 of the casing 10 is provided withside flanges 13 which retain the cover portion 10a in position whenassembled. The solenoid 24 and a bearing block are mounted in line onthe plate 14 so as to support the solenoid core 26 and the slidingspindle 22 in axial alignment. The bearing block 30 includes an axialrecess 32 to accommodate a sleeve bearing 34 guiding the spindle 22 andalso the spring 23 mounted over the upper end of the spindle. The upperend 21 of the spindle 22 is threaded and a pair of stop nuts 35 mountedon the spindle end provide a means of adjusting the spacing between thestamping surface 19 of the stamping device 20 mounted on the lower endof the spindle and the surface of the can to be stamped. Preferably, thespindle is adjusted so that there is about 4:" space between the top ofthe can and the stamp when the solenoid core 26 is fully extendedagainst the spindle 22 so that the spindle travels this remaining /s" byits own momentum. This preferred setting of course may necessarily haveto be increased if the rims of the cans are equal to V8" or more so asto ensure clearance of the stamp on the rebound or up stroke.

At the same time, the printing head 20 performs a slight pivotalmovement bringing the type face into progressive printing contact withthe can head during the momentary contact to further reduce thepossibility of smearing or blurring of the printed impression if thecans are being conveyed at relatively high speeds. For this purpose theprinting head 20 is made as having a type supporting base 33 having acorrugated surface adapted to receive interchangeable type and which ismounted between spaced supporting plates 39. The other ends of theplates 39 are pivotally mounted, as indicated at 25, to a supportingframe 43 secured to the lower end of the spindle 22. A shaft 31 extendsbetween the plates 39 at a position offset from the pivotal connections25 and compression rods 45 extend from the shaft 31 at each side to aloose connection with the frame 43. Springs 37 are mounted over each ofthe rods 45 between the frame 43 and shaft 31 and act as kickcompression members to accelerate the pivotal movement of the printinghead 20. This pivotal movement is caused initially, during the stampingmovement of the spindle 22, by the frictional contact of a leading edgeof the type face mounted on the base 33. To make this frictional contactmore positive the leading edge of the type face is provided with acontact or delivery bar 47, preferably of rubber or the like, see FIGURE8. As each contacted can proceeds, the engagement of the bar 47 causesthe printing head 30 to pivot about the axes 25 bringing the selectedtype face progressively into printing contact with the surface of thecan.

Almost immediately this pivotal movement has displaced the compressionrods 45 past the centre of the pivotal axes 25 so that the springs 37,which were compressed, now aot to accelerate the pivotal movement, seeFIGURE 9. In order that the printing head be returned to' ready positionfor each stamping with the springs 37 compressed, each plate 39 isprovided with an outstanding cam portion 41 which is adapted to engage astop 49 on the upward movement of the spindle 22.

In the construction shown, means in the form of swinging inking arms areprovided to supply the printing surface of the stamp with ink betweeneach printing stroke. In the construction shown, the bearing block 30includes a' forward extension 36 to which there is pivotally mounted ateach side inking arms 38. Each of the inking arms 38 is provided on itsinner surface with throwoff rails 40 which are engaged by correspondingthrowotf rollers 42 mounted on each side of the upper portion of thestamping head 20. Inking pads 50 are mounted between the inking arms 38with the arms being normally biased against the printing surface of thestamping device 20 by a coil spring 53. With this arrangement, when thespindle 22 descends the throw-01f rollers 42 engage the rails 40 pushingthe inking unit clear. When the spindle 22 retracts under the influenceof the spring 53 the inking pad 50' again swings up into contact withthe printing type.

In order that the cans A be guided into positive contact with theactuating switch 28 a pair of guide rails 60 are provided which aremounted one at each side of the conveyor run. These rails 60 aresupported on adjustable sliding rods 62 so that the spacing between theopposed rails may be varied to suit any desired size of can A. The rodsare supported in blocks 64 suitably bored to slidably accommodate therods 62 and provided with thumbscrews 66 so that the rods can be lockedin the desired position. The blocks 64 shown are each provided with athreaded pin 66 so that they can be assembled to the conveyor bydrilling and tapping suitable holes in the conveyor frame. The ends ofthe guide rails 60 can be bent to any desired radius to suit the size ofcans. With this arrangement, assuming the guide rails 60 are set to suitthe diameter of the cans A, as the center of each can passes the switch28 it actuates the solenoid 24 causing the stamping action described.

A suitable circuit is shown diagrammatically in FIG- URE 10 and it willbe noted that this includes a timer 70 which provides an impulse to thesolenoid having a duration only of about /6 of a second. This is toprevent double image which could possibly occur if the solenoid wereenergized during the full period of travel of a can beneath theapparatus which at times might be as long as 2 or 3 seconds. If thesolenoid remains energized the stamping head spindle 22 on completingits free travel, rebounds due to the spring 23 and hits the energizedsolenoid core 26. This sometimes lifts the core slightly off its seatbut the solenoid instantly urges it down again reactuating the spindle22.

As indicated generally in FIGURE 11, a preferred alternativeconstruction utilizes an air cylinder having a'spring biased piston 82in the place of the solenoid 24 and plunger core 26. This arrangementincludes a solenoid operated valve 86 to control the air under pressureto the cylinder 80. The circuit shown in FIGURE is also suitable forthis arrangement, the solenoid indicated being the controlling valvesolenoid 86. The remainder of the construction is the same as previouslydescribed and illustrated.

If desired, the timer 70 can be dispensed with and the problem ofpossible double image overcome by a mechanical arrangement as shown inFIGURE 12. This consists of having the lower end of the solenoid core 26or the piston stem 82 threaded and mounting a hollow cup 94 thereon. Ashock dampening disk 96, preferably of sponge-like cellular plastic orthe like, is inserted in the cup 94 so as to dampen or prevent arebounding of the stamp-ing head spindle 22. The only change necessaryin the circuit shown is the elimination of the timer 70.

As shown most clearly in FIGURES 4 and 11, the easing back plate 11supporting the solenoid 24 or the air cylinder 80 is provided withspaced apart supporting angles 13a, 13b having elongated attachmentslots 90 to which the solenoid 84 or the air cylinder 80 is attachedwith nuts and bolts 92 so as to permit adjustment of the actuatingmembers relative to the spindle 22. The bearing block 30 is fixedlyattached between the angles 13a, 1311 by screws 31. Accordingly, thestroke of the spindle 22 relative to the cans A can be adjusted throughthe stop nuts 35' and the position of the solenoid core 26 or piston 82relative to the spindle 22 adjusted to suit.

I claim:

1. An automatic stamping apparatus adapted to apply a stamp code indiciain sequence to each of a plurality of articles continuously fed pastsaid apparatus along a conveying path, said apparatus comprising asupporting standard member mounted across the convey-ing path, a plungersupporting and actuating member mounted on said standard above and inalignment with said conveying path, a plunger slidably mounted in saidactuating member for driven reciprocal movement towards said conveyingpath,

means controlled by contact of each of said articles adapted tointermittently actuate said plunger actuating member, a bearing blockmounted on said standard and a spindle slidably mounted in said bearingblock in spaced axial alignment from and in axial alignment with saidplunger with one terminal end of said spindle separate from and directlyopposed to one terminal end of said plunger, a spring connected to andresiliently biasing said spindle terminal end towards said plungerterminal end, an indicia bearing stamp mounted for restricted pivotalmovement on the terminal end of said spindle remote from said plunger,and resiliently biased compression members to align a forward edge ofsaid stamp indicia bearing surface with the moving surface of an articleto be stamped, said indicia bearing stamp forward edge supporting aresilient contact bar whereby on the downward stroke of said spindle thefrictional engagement of said contact bar on said article is adaptedthrough the movement of said article against said frictional engagementto pivot said indicia bearing stamp about said spindle connectionprogressively applying said indicia bearing surface to said article in adirection opposed to the movement of said article, and stop means onsaid standard adapted to engage and return said indicia bearing stamp toready position on the upward stroke of said spindle.

2. An automatic stamping apparatus adapted to apply a code indicia insequence to each of a plurality of articles continuously fed past saidapparatus along a conveying path, said apparatus comprising a supportingstandard mounted across the said conveying path, a plunger supportingand actuating member mounted on said standard above and in alignmentwith said conveying path, a plunger slidably mounted in said actuatingmember for driven reciprocal movement towards said conveying path, abearing block mounted on said standard and a spindle slidably mounted insaid bearing block in spaced relationship from and in axial alignmentwith said plunger with one terminal end of said spindle separate fromand directly opposed to one terminal end of said plunger, a springconnected to and resiliently biasing said spindle terminal end towardssaid plunger terminal end, an indica bearing stamp pivotally mounted onthe terminal end of said spindle remote from said plunger, resilientlybiased compression members acting on said stamp to accelerate thepivotal movements thereof, and a resilient contact bar mounted on aforward edge of said indicia bearing stamp in a position to firstcontact said article by frictional engagement during the stampingmovement of said spindle towards said article and urging said indiciabearing stamp into resiliently biased pivotal movement to progressivelyapply indicia supported by said stamp against an article contactedthereby in a direction opposed to the movement of said article, controlmeans responsive to the contact of articles fed along said conveyingpath connected to and adapted to actuate said plunger actuating meansand including a contact switch disposed in the path of said conveyedarticles, the stroke of said plunger when actuated and said spindlebeing adjusted relative to each other and the distance to the surfacesof the articles to be stamped being such that the final stamping contactof said stamp with each of said articles is created solely by thecontinued travel of said spindle against said spring after thetermination of said plunger stroke.

3. An automatic stamping apparatus as claimed in claim 2, wherein saidplunger actuating means comprises an electrical solenoid and saidplunger comprises a solenoid core, said contact switch being connectedto said solenoid core.

4. An automatic stamping apparatus as claimed in claim 2, wherein saidplunger actuating means comprises a fluid pressure cylinder and saidplunger comprises a spring biased piston, said control means including asolenoid valve connected to said fluid pressure cylinder and to saidcontact switch.

References Cited in the file of this patent UNITED STATES PATENTS2,443,779 Sanders et al. June 22, 1948 2,559,455 Meyer July 3, 19512,578,830 Park et a1 Dec. 18, 1951 2,787,950 Dorsch Apr. 9, 1957

